Remove container on load if it exited

If the shim gets sigkilled while containerd is down we need to be able
to remove the container correctly so that it does not stay in a stopped
state forever.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

runtime/container.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
 
 	"github.com/Sirupsen/logrus"
@@ -200,7 +201,9 @@ func (c *container) readSpec() (*specs.PlatformSpec, error) {
 }
 
 func (c *container) Delete() error {
-	return os.RemoveAll(filepath.Join(c.root, c.id))
+	err := os.RemoveAll(filepath.Join(c.root, c.id))
+	exec.Command(c.runtime, "delete", c.id).Run()
+	return err
 }
 
 func (c *container) Processes() ([]Process, error) {

runtime/container_linux.go

@@ -38,14 +38,10 @@ func getRootIDs(s *specs.PlatformSpec) (int, int, error) {
 
 func (c *container) State() State {
 	proc := c.processes["init"]
-	if proc == nil || proc.pid == 0 {
+	if proc == nil {
 		return Stopped
 	}
-	err := syscall.Kill(proc.pid, 0)
-	if err != nil && err == syscall.ESRCH {
-		return Stopped
-	}
-	return Running
+	return proc.State()
 }
 
 func (c *container) Runtime() string {
@@ -53,11 +49,11 @@ func (c *container) Runtime() string {
 }
 
 func (c *container) Pause() error {
-	return exec.Command("runc", "pause", c.id).Run()
+	return exec.Command(c.runtime, "pause", c.id).Run()
 }
 
 func (c *container) Resume() error {
-	return exec.Command("runc", "resume", c.id).Run()
+	return exec.Command(c.runtime, "resume", c.id).Run()
 }
 
 func (c *container) Checkpoints() ([]Checkpoint, error) {
@@ -336,6 +332,7 @@ func waitForStart(p *process, cmd *exec.Cmd) error {
 	return errNoPidFile
 }
 
+// isAlive checks if the shim that launched the container is still alive
 func isAlive(cmd *exec.Cmd) (bool, error) {
 	if err := syscall.Kill(cmd.Process.Pid, 0); err != nil {
 		if err == syscall.ESRCH {

runtime/process.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"syscall"
 
 	"github.com/docker/containerd/specs"
 )
@@ -36,6 +37,8 @@ type Process interface {
 	Stdio() Stdio
 	// SystemPid is the pid on the system
 	SystemPid() int
+	// State returns if the process is running or not
+	State() State
 }
 
 type processConfig struct {
@@ -178,6 +181,17 @@ func (p *process) Close() error {
 	return p.exitPipe.Close()
 }
 
+func (p *process) State() State {
+	if p.pid == 0 {
+		return Stopped
+	}
+	err := syscall.Kill(p.pid, 0)
+	if err != nil && err == syscall.ESRCH {
+		return Stopped
+	}
+	return Running
+}
+
 func (p *process) getPidFromFile() (int, error) {
 	data, err := ioutil.ReadFile(filepath.Join(p.root, "pid"))
 	if err != nil {

supervisor/supervisor.go

@@ -272,12 +272,12 @@ func (s *Supervisor) restore() error {
 		logrus.WithField("id", id).Debug("containerd: container restored")
 		var exitedProcesses []runtime.Process
 		for _, p := range processes {
-			if _, err := p.ExitStatus(); err == nil {
-				exitedProcesses = append(exitedProcesses, p)
-			} else {
+			if p.State() == runtime.Running {
 				if err := s.monitorProcess(p); err != nil {
 					return err
 				}
+			} else {
+				exitedProcesses = append(exitedProcesses, p)
 			}
 		}
 		if len(exitedProcesses) > 0 {